GUILE_QUIET: need help with redirection

GUILE_QUIET: need help with redirection

[Matt Wette]

Hi All,

I'm working on an update to guile to output some messages (e.g., 
auto-compile) to a new
`current-info-port', which is set to stderr by default.   I also added 
update to output the
welcome message, ending in "Enter `,help' for help.".   However, this 
breaks the
`00-repl-server' test which is looking for that message.  The test forks 
guile and closes stderr,
so it won't see the message ordinarily.   I tried to fix by setting 
`current-info-port' to
`current-output-port'.   But that does not work.    I now see the 
welcome message printed to
the screen during the test.   I guess the message is sitting in the 
stderr output buffer before
the fork happens.   So, options are:
1) Leave welcome message as is, going to stdout.
2) Find a way to make 00-repl-server.test work.
3) Initialize current-info-port to stdout (ugly)
4) Add some other hook in system/repl/common.scm(repl-welcome) to deal 
with it (ugly)

Any ideas?

Matt

Re: GUILE_QUIET: need help with redirection

[tomas]

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On Sun, Oct 06, 2024 at 07:13:02AM -0700, Matt Wette wrote:
> Hi All,
> 
> I'm working on an update to guile to output some messages (e.g.,
> auto-compile) to a new
> `current-info-port', which is set to stderr by default.   I also added
> update to output the
> welcome message, ending in "Enter `,help' for help.".   However, this breaks
> the
> `00-repl-server' test which is looking for that message.  The test forks
> guile and closes stderr,
> so it won't see the message ordinarily.   I tried to fix by setting
> `current-info-port' to
> `current-output-port'.   But that does not work.    I now see the welcome
> message printed to
> the screen during the test.   I guess the message is sitting in the stderr
> output buffer before
> the fork happens.   So, options are:
> 1) Leave welcome message as is, going to stdout.
> 2) Find a way to make 00-repl-server.test work.
> 3) Initialize current-info-port to stdout (ugly)
> 4) Add some other hook in system/repl/common.scm(repl-welcome) to deal with
> it (ugly)
> 
> Any ideas?

Hm. Tough question. I think what the test reminds us of is that
your default above (stderr) is a backward-incompatible change,
so I'd be very coutious about that. Who knows whose's code this
might break (besides the test).

So leaving `current-info-port' at stdout as default seems the
safest bet.

Perhaps a command-line option to set `current-info-port' to one
of several useful values (i.e. stderr, but also a void port)
might be helpful.

Cheers
-- 
t

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Re: GUILE_QUIET: need help with redirection

[Matt Wette]

On 10/6/24 10:29 AM, tomas@tuxteam.de wrote:
> On Sun, Oct 06, 2024 at 07:13:02AM -0700, Matt Wette wrote:
>> Hi All,
>>
>> I'm working on an update to guile to output some messages (e.g.,
>> auto-compile) to a new
>> `current-info-port', which is set to stderr by default.   I also added
>> update to output the
>> welcome message, ending in "Enter `,help' for help.".   However, this breaks
>> the
>> `00-repl-server' test which is looking for that message.  The test forks
>> guile and closes stderr,
>> so it won't see the message ordinarily.   I tried to fix by setting
>> `current-info-port' to
>> `current-output-port'.   But that does not work.    I now see the welcome
>> message printed to
>> the screen during the test.   I guess the message is sitting in the stderr
>> output buffer before
>> the fork happens.   So, options are:
>> 1) Leave welcome message as is, going to stdout.
>> 2) Find a way to make 00-repl-server.test work.
>> 3) Initialize current-info-port to stdout (ugly)
>> 4) Add some other hook in system/repl/common.scm(repl-welcome) to deal with
>> it (ugly)
>>
>> Any ideas?
> Hm. Tough question. I think what the test reminds us of is that
> your default above (stderr) is a backward-incompatible change,
> so I'd be very coutious about that. Who knows whose's code this
> might break (besides the test).
>
> So leaving `current-info-port' at stdout as default seems the
> safest bet.
>
> Perhaps a command-line option to set `current-info-port' to one
> of several useful values (i.e. stderr, but also a void port)
> might be helpful.

Thanks.  All the other internal redirections  to info-port in guile
are formerly to stderr.  This is the one case where the
redirection is formerly stdout.  So, I don't like using stdout for
the exact reason you state above: it is not backward compatible.

Matt

Re: GUILE_QUIET: need help with redirection

[tomas]

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On Sun, Oct 06, 2024 at 10:37:38AM -0700, Matt Wette wrote:

[...]

> Thanks.  All the other internal redirections  to info-port in guile
> are formerly to stderr.  This is the one case where the
> redirection is formerly stdout.  So, I don't like using stdout for
> the exact reason you state above: it is not backward compatible.

Oh, you mean the welcome message was going directly to stdout, while
info-port was always going to stderr?

I see. Perhaps we need yet another port, say `greeting-port' (or even
`welcome-port', although that would sound too whimsical to me [1]),
which would go by default to stdout and can be redirected as needed?

Sounds a bit heavy-handed, but would tick all backwards-compat boxes.

Cheers
[1] Whimsical names, like ice-9 or car come back to haunt you,
   10 or 50 years later.

-- 
tomás

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Re: GUILE_QUIET: need help with redirection

[Dr. Arne Babenhauserheide]

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<tomas@tuxteam.de> writes:

> On Sun, Oct 06, 2024 at 07:13:02AM -0700, Matt Wette wrote:
>> 1) Leave welcome message as is, going to stdout.
>> 2) Find a way to make 00-repl-server.test work.
>> 3) Initialize current-info-port to stdout (ugly)
>> 4) Add some other hook in system/repl/common.scm(repl-welcome) to deal with
>> it (ugly)
>> 
>> Any ideas?
>
> Hm. Tough question. I think what the test reminds us of is that
> your default above (stderr) is a backward-incompatible change,
> so I'd be very coutious about that. Who knows whose's code this
> might break (besides the test).

I think the test can be a warning that there may be applications which
expect the welcome text to see that Guile is ready. So I agree that we
should not break that.

The use-case of this change is to silence the welcome messages, so just
-I (without argument) could also mean that the greeting message is not
shown.

Or we could use the GUILE_QUIET environment variable for that (as in my
original patch).

Best wishes,
Arne
-- 
Unpolitisch sein
heißt politisch sein,
ohne es zu merken.
draketo.de

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